Lead Immobilization and Hydroxamate Ligand Promoted Chloropyromorphite Dissolution

Table 1

Selected speciation constants used in model calculations.

Reaction	log𝐾
(CPY) Pb5(PO4)3Cl = 5Pb^2+ + 3PO4^3− + Cl^−	−80.85
DFOB^3− + H^+ = H(DFOB)^2−	10.87
H(DFOB)^2− + H^+ = H2(DFOB)^−	9.57
H2(DFOB)^− + H^+ = H3(DFOB)	8.97
H3(DFOB) + H^+ = H4(DFOB)^+	8.35
Pb^2+ + H(DFOB)^2− = PbH(DFOB)	10.0
Pb^2+ + H2(DFOB)^− = PbH2(DFOB)^+	9.25
Pb^2+ + H3(DFOB)^− = PbH3(DFOB)^2+	5.92
2Pb^2+ + H(DFOB)^2− = Pb2H(DFOB)^2+	16.29
Pb^2+ + H2O = Pb(OH)^+ + H^+	−7.597
Pb(OH)2 + 2H^+ = Pb^2+ + 2H2O	−17.094
Pb^2+ + 3H2O = Pb(OH)^−3 + 3H^+	−28.091
2Pb^2+ + H2O = Pb2(OH)^+3 + H^+	−6.397
3Pb^2+ + 4H2O = Pb3(OH)4^+2 + 4H^+	−23.88
4Pb^2+ + 4H2O = Pb4(OH)4^+4 + 4H^+	−20.888
2H^+ + PO4^−3 = H2PO4^−	19.573
3H^+ + PO4^−3 = H3PO4	21.721
H^+ + PO4^−3 = HPO4^−2	12.375
H2O − H^+ = OH^−	−13.997
Pb^+2 + PO4^−3 + 2H^+ = PbH2PO4^+	21.073
Pb^+2 + PO4^−3 + H^+ = PbHPO4	15.475